I'm a bit confused because when doing CG we're meant to avoid ingredients that aren't water soluble so that we can co wash them out, eg. don't use silicones as they will build up if not water soluble ones.

But, a lot of people including me use oils on the hair directly or as part of product. And oil isn't soluble in water.

So, will it build up on the hair like cones do (ie. weighing down and possibly preventing moisture getting into hair)? Or is oil somehow different in the way it acts? Or can come out with a co wash?

I asked myself this question the other day and I seem to remember I came up with a reassuring answer....but now I've forgotten it, and it was probably wrong anyway!! Can anyone help?